title: Severe obstructive sleep apnea impairs left ventricular diastolic function in non-obese men.
abstract: OBJECTIVE
  To evaluate whether obstructive sleep apnea (OSA) contributes directly to left ventricular (LV) diastolic dysfunction.
  
  
  METHODS
  Seventy-four non-obese male OSA (apnea hypopnea index (AHI)⩾5/h) patients without cardiac disease, hypertension or diabetes were enrolled. Echocardiography, pulse wave velocity (PWV) measurements and laboratory testing were performed in all patients. LV diastolic function was assessed by the transmitral flow velocity (E/A ratio), and mitral annular velocity (Ea) was derived from tissue Doppler imaging (TDI).
  
  
  RESULTS
  The E/A ratio and Ea in the severe OSA group (AHI⩾30/h) was significantly lower than those in the mild to moderate OSA group (5⩽AHI<30/h) (P<0.0001), whereas the S/D ratio, an indicator of pulmonary vein flow velocity, in the severe OSA group was significantly higher than that in the mild to moderate OSA group (P=0.04). AHI exhibited a statistically significant inverse correlation with the E/A ratio (r=-0.47, P=0.0001), but not with relative wall thickness (RWT), LV mass index (LVMI) or PWV. RWT, LVMI and PWV exhibited an inverse correlation with the E/A ratio. Multivariate linear regression analysis revealed that severe OSA was independently associated with the E/A ratio even after adjusting for age, insulin resistance, blood pressure, LV geometry, and PWV (β=-0.23, P=0.001).
  
  
  CONCLUSIONS
  These results indicate that severe OSA itself may contribute directly to LV diastolic dysfunction irrespective of LV geometry, arterial stiffness, obesity and its associated cardiovascular risk factors.
authors.affiliation: Department of Cardiology, Tokyo Medical University, Shinjuku-ku, Tokyo, Japan. kaoyasu@tokyo-med.ac.jp
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Usui
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Takata
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Inoue
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Tomiyama
authors.forename: Saiko
authors.initials: S
authors.lastname: Kurohane
authors.forename: Yuki
authors.initials: Y
authors.lastname: Hashimura
authors.forename: Kota
authors.initials: K
authors.lastname: Kato
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Saruhara
authors.forename: Kihiro
authors.initials: K
authors.lastname: Asano
authors.forename: Kazuki
authors.initials: K
authors.lastname: Shiina
authors.forename: Akira
authors.initials: A
authors.lastname: Yamashina
mesh_terms: D000328:Adult; D001783:Blood Flow Velocity / Q000502:physiology; D015992:Body Mass Index; D001835:Body Weight / Q000502:physiology; D003971:Diastole / Q000502:physiology*; D004452:Echocardiography; D054459:Elasticity Imaging Techniques; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000503:physiopathology; D009765:Obesity / Q000150:complications / Q000503:physiopathology; D017286:Polysomnography; D063177:Pulse Wave Analysis; D012307:Risk Factors; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis* / Q000503:physiopathology*; D059289:Vascular Stiffness / Q000502:physiology; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis* / Q000503:physiopathology*